Frank a



P. A. FERRET. ELECTRIC CONTACT DEVICE.

(No Model.)

No 448,669. Patented Mar. 24,1891.

ATTORNEY Unirnn STATES PATENT @rricn.

FRAXK A. FERRET, OF BROOKLYX, NE W YORK, ASSIGNOR. TO TillC ELICKTRONMANUFACTURING COMPANY, OF SAME PLACE.

ELECTRIC CGNTACT DE iCE.

SPECIFICATION forming part of Letters Patent No. 448,669, dated March24, 1891.

Application filed June 28,1890. Serial No. 357,088. (No model.)

To all; whom it may C072/C07'7L: opposite the spaces between the holesof the lie it known that I, FRANK A. FERRET, a other row, and thediameter of the holes becitizen of the United States, residinginBrooking a little greater than the spaces between lyn, in the county ofKings and State of New the holes. 5 York, have invented certain new anduseful In the constr etion shown in Figs. 1 and 2 Improvements inElectric Contact Devices, of the upper ends of the holes arescrew-threaded which the following is a specification. to receivescrew-plugs a. In each hole is This invention has reference toimproveplaced a pencil of carbon of such diameter monts lllcarbon-brushes or contact devices that it will easily slide therein. Thepen- [O for conveying a current of electricity to and oils are all ofthe same size, and they project from a moving body, such as the commutaashort distance saya half inch or lessbetor of a dynamoclectric machineand is (10- low the lower side of the block. Between signed to obviatethe chief objections to cartheir inner ends and the screw-plugs arehon-brushes used heretofore, which are that placed coil-springs {ihaving a tendency to 15 however large the brush may be there is forcethe pencils out.

usually only one small part of it in actual \Vhen the device is used asa collectingcontact with the commutator, and that conbrush fordynamo-electric machines,the block sequently there is high resistance,heating, A is supported adjacent to the commutator and sparkingattending their use. I3 in such a manner that the pencils will 20 Myinvent-ion insures a number of good stand in radial planes against thesurface of contacts in each brush, and consequently rethe commutator.The block will of course be duces the rcsistanceand removes all tendencyconnected to an adjusting-yoke of any suittO spark. able description,and may be set as close to In general terms, theinvention consists ofthe commutator as desired. It will be ob- 25 a base or holder providedwith chambers, in served that with this construction I am able which areloosely placed pencils or blocks of to adjust the pressure of eachpencil against carbon,in combination with springs arranged the movingsurface independently of the to actindependently upon the respectivecarothers, and with the greatest delicacy, this bon pencils to forcethem toward the surface being accomplished by screwing the plugs a 3against which it is to make a working 0011- in or out. Owing to thelocation and diamtact. The pencils are easily removable from cter of thecarbon pencils, it will be observed the block whenever it is desired toreplace that the whole surface of the commutator rothem for any purpose.tating immediately beneath the block will be The invention will now bedescribed with covered by the pencils, so that the commutareference tothe accompanying drawings, in tor will be worn evenly instead of ingrooves, which as would be the case if arranged otherwise. Figure 1represents a perspective view of When brushes of the form shown in Fig.3- a block or holder with two rows of chambers; that is, with one row ofpencilsare used, the Fig. 2, a section of the same with screw-caps twobrushes are set so thatthe pencils of one 40 and carbons in place; Fig.3, a perspective brush will occupy the planes between the view of theblock with a single row of champencils of the other brush, as shown inFig. bers. Figs. i and 5 are views of modified This will also insureeven wearing of the forms. Fig. 0 is an end view of acommutator,commutator. I tind that the resistance of showing the position of thecontact device in this brush is very low and that sparking is 5 5relation thereto; and Fig. 7 a view showing reduced to a minimum, eachpencil being inhow a pair of the contact devices are set withdependently acted upon by its spring, conrespect to each other. stantand ample contacts are secured.

A represents the block or base, which may Fig. a shows the carbonsextending beyond be made of metal or any conducting subboth ends of theblock and with the sarings [00 5 stance. This block is provided. withtwo rows connected at one end to the head of the penof holes a, theholes of each row being placed oil and at the other end to the block. Inthis construction I use longer pencils and take advantage of the greatercontact-surface in the block, besides which the carbons may be removedand replaced with greater facility.

In Fig. 5 the perforations in the block do not extend entirely through,but are in the form of chambers, a spring being first placed in eachchamber and the pencils then putin.

My invention is not restricted to any particular form of chamber, holeor pencil, or to any particular number in each holder or any particularnumber of rows. The arrangement need not be in rows either, although Iprefer it;

Having thus described my invention, I claim 1. A contact device or brushconsisting of a block or holder provided with two rows of perforationsor chambers,the perforations or chambers of each row located oppositethe spaces between the perforations or chambers of the other row, thediameter of the perforations or chambers being greater than the spacesbetween the same.

2. A contact device or brush consisting of a block or holder providedwith a plurality of perforations or chambers, a carbon pencil in eachperforation or chamber, a spring for each pencil, and a separateadjusting device for each spring for varying the tension. 7

3. The combination, with a commutator, of a pair of brushes, eachconsisting of a holder and 'a row of pencils, the brushes being set withthe pencil of one brush standing opposite the spaces between the pencilsof the other brush, so that the wear on the commutator will be eveninstead of in grooves. 7

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses. v

' FRANK A. FERRET. Witnesses:

DANIEL FERRY, JAMES L. MADIGAN.

